GIS-Based Spatial Assessment of Urban Engineering Geological Conditions Using Borehole and Laboratory Data: A Case Study of Pavlodar, Kazakhstan

Assessment of urban engineering geological conditions is often constrained by the uneven distribution and variable completeness of site-investigation data. This study presents a GIS-based spatial assessment of ground conditions in Pavlodar, Kazakhstan, using archival borehole records and laboratory test results. The dataset comprises 523 georeferenced boreholes, 2147 engineering geological intervals, and 1373 laboratory-tested soil samples. Borehole data were standardized and integrated into a GIS database to characterize the spatial distribution and vertical succession of engineering geological elements (EGEs), soil-layer thicknesses, and groundwater depths. Laboratory data were analyzed to describe the deformation and strength characteristics of the principal soil groups and their relationships with the liquidity index. The study area is characterized by technogenic, alluvial–deluvial, and Neogene deposits with substantial spatial and vertical variability. Representative deformation modulus values are 20.0 MPa for Quaternary sands (EGE-3) and 35.0 MPa for Neogene sands (EGE-4), whereas Neogene clays show lower values of 7.3–15.6 MPa (EGE-5a–5c). Four preliminary foundation-condition types and one conditional subtype were distinguished according to soil composition, weak-layer thickness, depth to sandy strata, and occurrence of clayey deposits. The results provide a regional overview of urban ground conditions and can support preliminary planning of site-specific engineering investigations, although they require further verification before being applied to individual construction projects.